Medication of Diseases News - Part 2

Since the effect of alveolar hypoxia is local and is predominantly on the small muscular pulmonary arteries, the next problem is to localize the “hypoxia receptor” across the thickness of the alveolar-vascular barrier. To do this we must go back to the basic anatomy of the pulmonary arterial wall. Figure 3 showed a small muscular pulmonary artery adjacent to a bronchiole in a dog lung. The wall of the vessel is thin, averaging about 10 percent of the luminal radius. The vessel illustrated has a radius of 150 |x. Thus, its wall is about 15 |x thick, separating alveolar gas from mixed venous blood.

Female patients (n = 257) were significantly older and had a higher prevalence of diabetes and hypertension (Table 1). A longer delay from onset of symptoms to hospital admission was found in women (8 h vs 6 h). Women also presented with cardiogenic shock on hospital admission more frequently than men.

Reperfusion Therapy

Women were significantly less likely to receive fibrinolytic therapy than men (Table 2). This difference was explained, at least in part, by their older age and a longer time delay (adjusted odds ratio [OR] for reperfusion therapy, 0.84; 95% confidence interval [CI], 0.59 to 1.24) [Table 3].

In tetraplegic patients, immersion to shoulder level in isothermic water increased the SVC nearly 25% above basal measurements. However, a healthy control group showed the opposite pattern with an average reduction of 4%. Among the tetraplegic patients, the lower the preimmersion vital capacity, the greater was the percentage of improvement following immersion.

Only two prior investigations have studied the effect of immersion on the pulmonary function of subjects with tetraplegia, and agree with and complement the results of present study. In 1982, Jaeger-Denavit et al evaluated 12 tetraplegic subjects immersed in water (29 to 31°C) with “head out” and showed an elevation of vital capacity, accompanied by a fall in residual volume. In 1991, this reduction in residual volume was confirmed by Bosch and Wells in eight tetraplegic subjects immersed to the “neck” in water at 34°C. Neither study mentions the time of immersion. In spite of these similar results, the studies were conducted in different experimental conditions without considering the potential effect of water temperature and time of immersion on the results.

Eight hundred forty-three smokers were referred to the smoking cessation service from January 2000 to December 2002. Of these, 600 smokers were excluded due to exclusion criteria, being unable to be contacted for further intervention, or saturation of staff resources due to large referral numbers during busy periods. The remaining 243 smokers were recruited into the study. Twenty-seven of these subjects were excluded after enrolment due to inadequate attendance of the smoking cessation program (ie, they did not complete an initial visit plus two follow-up visits or phone contacts). Therefore, a total of 216 subjects who completed the smoking cessation program were evaluated; 187 never-smoker subjects were recruited as control subjects.

Sudden unexpected death occurring a considerable time after surgery in congenital heart disease, especially in tetralogy of Fallot, and after the Mustard procedure for transposition, is well documented. However, studies of the conduction system in these cases of sudden death are rare. Is the sudden death related to the previous surgery? Is it related to the changes in the anatomy or electrophysiology after surgery in some cases? Or is it similar to the unknown cause of sudden death seen in the general young population?

Studies of the conduction system in our four cases reveal abnormalities in this system which may be significant in the etiology of sudden death.

The first point to consider is the feet that in three cases, (1, 3, and 4), there was marked fibrosis, and arterio- and arteriolosclerosis of the summit of the ventricular septum, far beyond that seen normally in the respective ages. These changes were often associated with alteration in the central fibrous body and the pars membranacea. This anatomic pathology may be due to the altered hemodynamics after the operative procedure and possibly to the effects of the surgical handling of the heart. And since the conduction system lies within or adjacent to the fibrous skeleton of the heart, it may be affected by the changes of this skeleton, resulting in sudden death.

The object of the study is to define the minimum increase (or decrease) in tidal volume reliably detected by a subject. The subject produces a constant tidal volume (one method would be by targeting to a volume trace on an oscilloscope). A number of test stimuli are then administered. The test stimuli consist of the reference volume and the volumers bridging the detection threshold. Following the presentation of a reference tidal volume, the subject targets to a slightly bigger (or smaller) volume by altering the gain on the scope unknown to the subject—the visual target is the same. The subject is then asked to make a forced choice: Is the volume the same? (“yes” or “no”). After many trials the positive responses, expressed as a percentage of the total number of presentations for each tidal volume, are plotted against the tidal volume. The detection threshold is defined as the volume detected bn 50 percent of presentations, and the percentage of positive responses for the reference volume is taken as an index of response bias. The threshold volume is conventionally expressed as a fraction of the background volume to define the Weber fraction.

Tearning to perform fiberoptic bronchoscopic examinations requires only modest training. Confident manipulation, recognition, and proper interpretation of pathologic processes, and successful management of complications, require more experience. In order to maximize diagnostic accuracy in different situations encountered in fiberoptic bronchoscopic procedures, at least several other phenomena are important: careful processing of the samples obtained; highly skilled cytology, pathology, and microbiology support; and development of new instrumentation technology. Even these are not enough, however, if efficiency and economy are desired.

In the July issue of Chest (1985; 88:49-51), Shure and Fedullo have helped by identifying a subset of patients with bronchogenic carcinoma who have submucusal and peribronchial abnormalities; in their hands, diagnostic yield was significantly improved by adding transbronchial needle aspiration (TBNA) to other sampling methods. Similar superior diagnostic yield from TBNA in patients with endoscopic features of submucosal tumors have been reported by others.

Several limitations are present in this study. For many reasons, administrative databases routinely include incomplete and biased data that can significantly influence the numerators and denominators used in the analyses. In order to ensure homogeneity of the data sources, our study used the nationwide inpatient registries, which are established in each country included in this article by the ministry of health (government institutes). Due to the nature of the health systems in these countries as well as in Europe in general (“universal” health-care systems), uniform systems of delivery, financing, and tracking of health care within the countries are in place. Therefore, the nature of the data collection within each country is homogeneous, though there may well be differences between the countries

Large regional variations in hospitalization patterns found in this study are surprising in view of the sociodemographic, health status, and health-care system similarities among the four Nordic countries. Indicators like gross domestic product, percentage of gross domestic product spent on health care, public spending for health care per inhabitant, proportion of urban population, infant mortality rate, life expectancy at birth, and the number of physicians per 100,000 inhabitants, are very similar for the Nordic countries., In addition, asthma-specific mortality rates and access to specialist care as approximated by the presence of pediatric departments do not vary substantially. The prevalence of asthma in children also has been shown to be similar between countries, as well as between regions within Nor-way and Sweden.

Hospitalization rates may reflect reliance on hospitalization for asthma management and/or a lower level of asthma control in the primary care setting. Lack of disease control at the primary care level often results in higher hospital utilization. We previously introduced readmission rate as a measure of the efficiency of asthma management in the secondary care setting. Once the child has been hospitalized, it is largely a failure of the secondary care if readmission for asthma is needed. Hospital LOS also may reflect the efficiency of hospital-based asthma management. In this study, LOS showed geographic variations in concordance with the differences in hospital admission rates and RHR, which supports the validity of these measures.